Switch for lamp-circuits.



Patented June 26, I900.

E. l. DODDS. SWITCH FOR LAMP CIRCUITS. (Application filed Sept 9, 1899. Renewed May 14, 1900.)

(No Model.)

W/ T/VE 55 ES L Q? ATTORN UNITED STATES PATENT OF I E.

ETHAN I. DODDS, OF. AVALON, PENNSYLVANIA, ASSIGNOR TO GEORGE 'WESTINGHOUSE, OF PITTSBURG, PENNSYLVANIA.

SWITCH FOR LAM P'-C|RCUITS.

SPECIFICATION forming part of Letters Patent No. 652,597, dated June 26, 1900.

Applicatiml file September 9, 1899. Renewed May 14, 1900. Serial No 16,688. (No model.)

T0 on whom it may concern:

Be it known that I, ETHAN LDODDS, a citi-.

zen of the United States, and a resident of Avalon, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Switches for Lamp-Circuits, of which the following is a specification.

My invention relates to automatic switch devices adapted to be used in connection with lamps of the type in which the incandescing body or glower is at first a non-conductor of electricity and is brought to a conductive state by being heated from some external source.

The object of my invention is to provide a device through which the lamp can first be switched in, so as to close both the heater and the glower circuits, and which is so acted upon by the change in conductivity of the glowercircuit after the heater has done its workas to automatically break the heater-circuit and leave the glower-circuit complete. 7 y

In my present form of apparatus I employ a switch which is placed underspring tension impelling it in a certain direction, but

.moved still farther in the same direction by hand, thereby breaking the glower-circuit. The force of the spring is not completely spent when the switch has been brought to its second position, so that the spring assists the hand in this last operation and will maintain the switch in its third position after the hand has been used to break the lamp-circuit.

My invention willbe understood by reference to the accompanying drawings, in which Figure 1 is a plan of my switch, together with a diagram of the circuits and electric lamp controlled thereby. Fig. 2 is a side view disk A and is provided with an insulatinghandle D, secured to the said shaft by a pin d. Firmly connected to the shaft 0 is an insulating-plate E, to which isattached one end of a coil-spring c, the opposite end of which is attached to the disk A. When the handle D is turned to the left, it carries with it the plate E and puts the spring e under tension,

so that the said spring after such a movement to the left is made tends to carry the plate E to the right.

To the plate E are secured, by means of pivots 0 0, arms F and F, to which contactpieces G G, preferably of brass, are secured.

The said contact-pieces G and G are made cylindrical in shape, and the opposite ends thereof cooperate with contact-springs, as

shown in Figs. 3'and 4. For example, the contact-piece G is so placed as to come into and the contact-spring g is held to the insu- Suitable nuts 4 and 5 hold the screws 1 and 3 in lating-disk A by means of a screw 3.

place, as will be readily understood. The spring h is similarly held by a screw 6 to the top of an insulating-post 7, a nut 8 being pro-:

vided underneath the disk A for holding the screw 6 in place. The spring h is held by a screw 9 and a nut 10. The arm Fis pivoted within an opening in the plate E and is normally held against one wall of the'said opening by a spring 11. This spring is attached at its opposite ends to the arm F and to the projection 12 on the plate E. A preciselysiinilar construction is employed in connection with the arm E, which is held by a spring 13 to a projection 1% on the plate E. In the periphery of the plate E, which is generally circular in shape, are notches 15 and 16, and,

17, carrying a roller 18 at its free end. The said dog is pressed by a spring 19 against the plate E. In Fig. 5 I have illustrated the contact-piece G as being in contact with springs t' i. In this instance the springs are arranged, as before, to make contact with the ends of the contact-piece G, the spring i being supported upon a suitable post 20 and the spring 2" upon the disk A.

The disk A is formed with a rim or flange a at its lower edge to receive a metallic cap I), which covers the main operating parts of the switch already described. Underneath the disk A is supportedan electromagnet K, consisting of a coil of wire suitably held in an angular frame of iron. The means for holding the magnet to the disk is a screw L, (shown in dotted lines in Fig. 2,) the said screw being passed down through the disk A and extending into the frame K, with an interposed insulating-washer M. The electromagnet K has an armature N, pivoted to the frame K at 70 and perforated outside said pivot, so as to surround a neck 1) on a vertical rod P, passing up through the disk A. At the bottom of the rod P is a head q, and the said head, together with a shoulder r on the rod P, constitutes surfaces between which the armature N rests with a slight intervening space. The rod P is normally forced upward by a spring 21, which rests upon the disk A and presses atits opposite end against a pin 22, projecting from the said rod. The upper end of the rod is in the path of a tooth or projection 23 on the periphery of the plate E.

The circuits controlled by the described switch start in the first instance from any suitable generator S, which I represent in this instance as supplying two separate converters T and T. In the circuit of the converter T, I locate the heater 2% in proximity to a glower 25 in the circuit of the other convertromagnet has been removed from the glower, g circuit. any unnecessary resistance being included f in the circuit of the glower, although I do'not exclude from the said circuit such ballast re= lsistance as may be necessary to steady the action of the glower.

ter. Now the heater circuit includes two wires 26 and 27, running, respectively, to the contact-sprin gs g g. The glower-circuit is divided into branches, one of which is made up of two wires 28 and 29, the former of which extends through the electromagnet K to the contact-spring h and the latter of which extends to the contact-spring h. The second branch of the glower-circuit passes by way of wires 30 and 31 to the contact-sprin gs it, respectively.

The first operation of the switch consists in turning the handle D to the left until the tooth or projection 23 slips over the end of the rod P, the said end of the rod P being beveled off, so as to permit the said rod to be pressed down by the force of the hand movement which accomplishes the said first operation of the switch. The switch is then released, but is held from returning to its original position by the engagement of the catch formed by the top of the post- P with the tooth 23. The described operation brings the respective switch-contacts into the positions illustrated in Figs. 3 and 4, so that the heater-circuit is completed and that branch of the glower-cu cuit is complete which passes through theelectromagnetK. Thislast-named circuitisheld inoperative by reason of the non-conducting quality of the glower 25 when in a cold state. However, the heater-circuit being closed, the heater is brought to so high a temperature as presently to make the glower 25 conductive through raising its temperature. Thereupon the branch circuit which includes the electromagnet K is energized, thus bringing the said magnet into operation and drawing up its armature N. This results in pulling down the rod P far enough to release the tooth 23, whereupon the plate E is thrown into power of the spring a. The first effect of this release is to cause the springs 11 and 13 to be stretched some, owing to the fact that the respective contact-springs g g and h h stand somewhat in the way of the contact-pieces G G, whereby they tend to resist the free exit of said contact-pieces from the openings between the said springs. However, the spring e, being more powerful, overcomes the resistance of the contact-sprin gs, and the separation of the contact-pieces G and G from the said contact-springs takes place with a quick sudden movement. At the same time the roller 18 enters the opening 15, and through the force of the increased leverage which said spring-dog possesses when the roller is in the said opening andalso through the fact that the springs t t in like manner resist the free passage of the conj tact-piece G between them the moving parts of i the switch are held in such position as to keep the contact-piece G in contact with the springs '5 '6. Meanwhile, however, the contact-piece 1G has become separated from the contact springs it h, whereby the heater-circuit has l been ruptured. Similarly, the branch circuit i which includes the eleetroin-agnet K has been ruptured, and the resistance of the said elec- The lamp will now operate without A ballast resistance of this sort is shown at 32 in series with the glower. The lamp is permitted to burn aslong as may be desired and is then extinguished by operating the switch still farther to the right by applying the hand to the handle D. All the 1amp-circuits are then broken and the lamp is out of service.

The invention claimed is- 1. The combination with a glower of the type described and an electric heater therefor and separate circuits for the said glower and heater, of means for closing both circuits simultaneously, and automatic means for breaking the heater-circuit by a quick sudden movement when the glower-circuit has become active.

2. The combination with a glower of the type described and an electric heater therefor and separate circuits for the said glower and heater, of a spring-actuated switch held bya suitable catch, a trip for the said catch included in the glower-circuit, means for putting the springs under tension and closing the circuits of both the glower and heater, and means for operating the said trip when the glower-circuit becomes energized.

3. The combination with a glower of the type described, and an electric heater therefor and separate circuits for the said gloWer and heater, of a spring actuated switch held bya suitable catch, an electromagnetic trip for Witnesses:

WM. H. CAPEL, GEORGE H. STOCKBRIDGE. 

